Yes. Even if they survived the cliff fall in their car, because the nearest hospital, and therefore death avoidance, was very far.

Imagine that they flew off of the cliff and their car crashed at the bottom and one of them survived.The injuries sustained, at minimum, would not allow them to walk away from the accident, let alone walk far enough to reach a hospital. So, even if they survived the crash, without cell phones, there is no way for them to reach a hospital or go far enough to find civilization/survive.